Tungsten is used as the target material on the tube's anode because it has a _____ atomic number and a _______ melting point.
a. low, high
b. high, low
c. low, low
d. high, high

d

________ scanner design was the first to acquire four slices in a single rotation.
a. second-generation
b. third-generation
c. multi-row detector
d. continuous rotation

c

The enormous heat that builds up in the tube is caused by the:
a. intensity of the x-rays emitted from the tube
b. electron beam between the cathode and the anode in the tube
c. x-ray filter in the tube which absorbs the lower energy photons before they can enter the patinet
d. collision of the electorn beam with the tungsten target on the tube anode

d

The number of electron that flow from the cathode to the anode in the tube is controlled by the:
a. anode target
b. collimation
c. mA
d. kV

c

The slip ring on continuous rotation CT scanners:
1. prevents the high voltage cable from winding up
2. allows the exam to commence more rapidly
3. eliminates the need for the reversal of gantry frame rotation
a. 1 only
b. 2 only
c. 3 only
d. 1, 2 and 3

d

Which of the following is NOT a part of the CT tube?
a. tungsten target
b. collimator
c. rotating anode
d. filament

b

Which of the following are NOT commonly used on today's commercially available CT scanners?
1. xenon detectors
2. fourth-generation technology
3. continuous rotation technology
a. 1 only
b. 1 and 2
c. 2 and 3
d. 1, 2 and 3

X-ray photons are produced by a fast-moving electron:
1. colliding with an atomic nucleus
2. passing close to an atomic nucleus
3. colliding with an electron within an atom and ejecting it
a. 1 only
b. 2 only
c. 3 only
d. 1, 2 and 3

d

Which of the following is TRUE regarding solid state detectors?
1. x-ray photons cause the detectors to generate a flash of light
2. they are the detector type used on most CT scanners today
3. they can be used in both third-generation and fourth-generation CT systems
a. 1 only
b. 2 only
c. 3 only
d. 1, 2 and 3

What control does the operator have over the x-rays in a CT exam?
a. the temperature and color of the x-rays can be tuned
b. the energy level and the quantity of x-rays can be selected
c. the volume and tone of the x-rays can be dialed
d. the phase and frequency of the x-ray can be adjusted

b

Which of the following statements is TRUE?
1. kV is the voltage potential between the tube cathode and anode while mA ultimately controls the filament current and, thus the temperature of the cathode filament
2. kV controls the energy level of the x-ray photons and mA controls the nubmer of x-ray photons emitted from the tube
3. althought the kV and the mA affect the operaton of the CT x-ray tube, the two parameters have no bearing on the image quality
a. 1 only
b. 2 only
c. 1 and 2
d. 2 and 3

c

Which of the following does NOT affect the quantity of x-rays that completely penetrates the patient?
1. the distance that the x-ray photons must travel on their course throught the patient's body
2. the molecular composition of the tissues through which the x-ray photons pass
3. the type of detector material used
a. 1 only
b. 2 only
c. 3 only
d. 1, 2 and 3

Which of the following statements is FALSE regarding the collection of CT data?
a. long scan times are more desirable because they average out motion artifacts
b. the reconstruction process used to create the image occurs in the array processor
c. to collect the complete set of CT data, x-rays must be passed through the body at many different angles
d. the detectors measure x-rays which completely penetrate the patient

a

Which of the following is a component NOT normally located in the gantry of a modern CT system?
a. pre-patient collimators
b. solid-state detectors
c. array processor
d. x-ray tube

c

X-rays are used in CT because:
a. they are easily produced by the high frequency generator
b. they are less harmful then the heating effects of microwave radiation
c. they penetrate the body according to specific attenuation characteristics of each tissue
d. the FDA imposes no limit on the dose to the patient

c

X-rays are produced whenever fast-moving electron collide with any form of matter because:
1. the electron splits into two x-ray photons of equal energy upon impact with the matter
2. the electron loses kinetic energy which is converted into the emission of an x-ray photon
3. the electron converts the electron it collides with into an x-ray photon
a. 1 only
b. 2 only
c. 3 only
d. 1, 2 and 3

b

Bremsstrahlung radiation does NOT include which type of electron activity?
1. collision between an incoming electron and the nucleus of the target atom
2. collision between an incoming electron and an electron in an inner shell of the target atom
3. slowing down of an incoming electron due to the effect of passing close to the positive charge of the necleus of the target atom
a. 1 only
b. 2 only
c. 3 only
d. 1, 2 and 3

Which of the following is NOT a function of a PACS system?
a. reconstruction of the image from the raw data
b. long term data storage
c. digital distribution of images
d. image display for the radiologists

a

Which of the following is TRUE regarding multi-row detector CT scanners?
1. the size of the detector arrays along the z-direction may be different
2. the attenuation information from adjacent detector arrays may be added together to generate thicker slices
3. all of the detector arrays may or may not be used
a. 1 only
b. 2 only
c. 3 only
d. 1, 2 and 3

d

Which of the following is FALSE regarding CT systems?
1. they are limited to non-oblique transverse scanning
2. they cannot generate a straight coronal or sagittal image
3. they have no moving parts
a. 1 only
b. 2 only
c. 3 only
d. 1, 2 and 3

d

Most of the commands from the technologist are received by the:
a. array processor
b. operator's console
c. host computer
d. amplifier

Which of the following CT scanner designs does NOT use an x-ray tube?
a. first-generation CT
b. PET/CT
c. electron beam CT
d. MDCT

c

Tube interscan delay time refers to:
a. the time between the end of one scan and the start of the next scan during which the tube will cool
b. a quality assurance test performed daily by the technologist
c. the time required for the tube to make a complete 360* revolution about the gantry
d. the length of time required for the production of photons to begin after applying the voltage to the tube

a

On a single-row detector scanner, collimation:
1. controls the slice thickness
2. minimizes the x-ray dose to the patient
3. reduces the detection of scatter radiation
a. 1 only
b. 2 only
c. 3 only
d. 1, 2 and 3

d

The main purpose of the detector is to:
a. provide additional collimation in order to reduce scatter
b. limit the x-ray dose to the patient
c. capture x-ray photons and convert them to a measurable signal
d. amplify the measured signal

c

In order for an x-ray photon to be measured it must:
1. enter the detector chamber
2. be absorbed by the detector material
3. be converted to a measurable event
a. 1 only
b. 2 only
c. 3 only
d. 1, 2 and 3

d

The patient table:
a. may move continuously during the scan
b. can never be positioned automatically by software due to safety precations
c. remains stationary throughout the patient exam once it is initially positioned
d. only moves after each slice is completed

a

Which of the following statements is FALSE regarding occurrences after an x-ray photon penetrates the detector aperture?
1. the photon can pass through the detector unmeasured
2. the photon is converted completely into an electron
3. the measured signal is enhanced by an amplifier
a. 1 only
b. 2 only
c. 3 only
d. 1, 2 and 3

b

CT images can be directly scanned in planes other then transverse by:
1. orienting the patient's body part so that is is not perpendicular to the x-ray beam
2. tilting the gantry
3. changing the angle that the x-ray beam leaves the tube
a. 1 only
b. 1 and 2
c. 2 and 3
d. 1, 2 and 3